What do systematic reviews say?

Summary of findings table ‐ immunostimulant vs placebo

Summary of findings table ‐ immunostimulant showed no clear difference in mortality (respiratory‐related) compared with placebo (low certainty).

• Immunostimulants versus placebo for preventing exacerbations in adults with chronic bronchitis or chronic obstructive… 2022 · Cochrane Headline outcomes only
  OR 0.4 [0.15, 1.07]
  2 studies · 735 participants
  Low